You're a Chemical That Burns, There's Nothing Like This
by fadingxintoxfantasy
Summary: "Saitama looked up from his book, taking in his cyborg's bloody appearance. 'You wear victory well, Roomba,' he said, starting to feel something at the sight of the blood trickling down his lover's cheek. He swallowed. 'I suppose I should reward you for doing so well...'" content warnings: graphic descriptions of violence -villain au-


A trail of blood droplets followed Genos home. He was smothered in monster and human blood, and he was simply glowing. It had been an exhilarating killing spree. He had promised to come home to Master from patrols in one piece because he wanted to do it alone. To prove to him that he had indeed gotten stronger. He didn't have to worry about being torn to pieces by any monster he encountered.

Indeed, his speed and accuracy had improved immensely, and he single-handedly defeated a rather strong creature over twice his size and girth. He finished the fight without so much of a _scratch._ He almost did wish that Saitama was there to see how well he did- how far he had come.

And then there were the spectators of Genos' battle. The cyborg had beaten any heroes to the scene, so he was the only one fighting it. When it was finally slain, a man spat at him, calling him 'evil.' Usually a title like that wasn't something he minded;however, he had the _audacity_ to insult Master.

"You and that lazy, bald fuck should rot in hell," the foolish man jeered.

The buzz from defeating the monster boiled into a white-hot rage, and Genos quickly found himself standing right in front of the man, shoving his blade-fingers into his abdomen, twisting and clawing. He reveled in the sight of the man's face contorting in the incomprehensible pain. Pain that neither he nor Master could feel. He came to realise that he was actually doing this foolish man a favor in killing him, and there was a sort of beauty in watching the light burn out of his eyes. Of course, this beauty wasn't something that Genos had not noticed before- in fact it was one of the more delightful things about killing. In this moment, however, he found a greater purpose in it because no one deserved to live in a world where they could not recognise just how perfect Master was. Jerking his claws out of the man, his entrails stuck to the blades as the corpse fell to the ground.

"Does anyone else have anything the would like to say about my Master?"

A few people sobbed, some screamed, others looked at him, utterly petrified.

That was enough for Genos.

So, with blood dripping off of him into the dips of his armor and down his face, he returned home.

* * *

"Master," he said through the entry-way, "I'm home."

"How did it go?" Saitama asked from the living area. Genos stood at the walkway, looking at his Master lounging against their folded futon, reading a manga.

"I defeated it."

Saitama looked up from his book, taking in his cyborg's bloody appearance. "You wear victory well, Roomba," he said, starting to feel something at the sight of the blood trickling down his lover's cheek. He swallowed. "I suppose I should reward you for doing so well. But first, tell me- how did it feel?"

Genos leaned against the wall, getting some blood on it. "Master it was incredible. I was able to apply everything I learned from you. Granted, it was only a demon-level being; however, I arrived there before any heroes, thus showing my competence over them. The actual fight lasted fifteen minutes and thirty seconds. At times I felt myself fatigue because of its speed. I didn't back down, though. I never lost a hit by mistakenly following an after image. As the fight progressed, I found that its underbelly was simply too thick to deliver a fatal wound to, so I worked toward getting closer to its neck. When I finally did so, the blow was so intense that my entire arm was submerged. It perished almost immediately."

Having gotten used to Genos' monologues by now, Saitama patiently listened to his story, as feelings of pride, envy, and desire bubbled inside him. Genos really had improved. It sounded like he was being more conscious of how he fought, that he was developing strategies. Anything that would bring Genos home in one piece was something that Saitama was immensely grateful for. In fact, he had taken up giving his lover actual advice because he simply could not handle bringing Genos to Kuseno in pieces every time they had a complicated battle. His cyborg was far too important to him now. It scared him whenever Genos got hurt because he couldn't imagine his life without him anymore. So, he finally buckled down and came up with ways he could help his disciple. Granted, he wasn't a great teacher either way but at least some of his advice yielded results.

"You were amazing, Roomba. I don't know how else to say it."

"Can you show me, Master?"

* * *

The door to the bathroom was kicked shut as Saitama's mouth consumed Genos'. He pressed the cyborg against the door, pinning his wrists down as his tongue found tastes that he never knew would get him so excited. He knew the kid had a habit of tasting his victims but he never understood it until now. If he couldn't feel Genos' victory; he could sure as hell taste it in his mouth. And why stop there?

Saitama moved to Genos' jaw, kissing, nipping, and licking. Genos was ready to melt. He knew it was fruitless to attempt to touch Saitama when he had his arms pinned down, but he desired it all the same.

"Master…" he whined.

"Mmm hold on~" Saitama growled before moving to nibble at the cables in his lover's neck. To Genos it felt like the most tender pinches. He often had to disable his HUD when he and Saitama made love because his body was constantly trying to label the love bites as threats, but in reality it made Genos all the more turned on. He could feel his Master's teeth disrupting the flow of electricity like a temporary circuit-breaker- flow returned, the electricity jumped back and forth, back and forth- forcing Genos to activate his cooling subroutines, and subsequently causing steam to fill whatever room they were in.

"Feels so good, Master."

"Undress. I'm going to start the shower."

Genos did as he was told, peeling the bloody clothes off. A lot of it had seeped through his clothes- red tinted the silver and black of his body. After Saitama started the shower he undressed, revealing his already-hard length.

He took Genos' hand and pulled him in the shower. Before he did anything with Genos, he wanted him good and clean. As much as he liked seeing his cyborg covered in the blood of their enemies, he enjoyed cleaning him up more.

The water cascaded over the both of them, and despite Genos being unable to feel temperature, he always loved the feeling of water. It was the pressure mostly. And the little sparks it sent through his body. And with Saitama showering was even more pleasant. It never took long for his Master's hands to find his scalp, gently massaging rosemary shampoo through his hair. The synthetic muscles in him relaxed completely, melting at Saitama's touch.

* * *

Cleaned and dried, Saitama guided Genos back into the living area. He unfolded the futon, laying Genos on top of it. After kissing him tenderly, he stood up tall- a coy grin spreading on his face.

"What colour are you in the mood for?"

"I'm sorry?"

"I want to dress you."

"Oh," Genos sounded, thinking a moment. He knew that Master was referring to his lingerie, but he had quite a collection to choose from.

"Emerald," he said finally.

Saitama's grin widened, already delighted at the thought of his lover in that colour. He moved over to the closet, and started digging through the chest of drawers Genos had put in there. It mostly contained Genos' stuff, but one drawer had Saitama's underwear. After slipping on his own underwear, he rifled through a little more thoroughly and found the emerald green ensemble Genos requested. Thinking a moment, he decided black stockings would be nice too. Maybe Genos' impossibly high heels? God, he had really awakened some kind of lingerie kink in Saitama that he didn't even know he had. Weird. Anyway.

Bringing the lingerie and heels back to Genos on the futon, he took in the sight of his lover lying down, silver eyes locked on him. There was a time when Saitama found that unsettling, but now it was comforting. It was home.

He knelt down and unfolded the lingerie, holding up the panties.

"Oh. I almost forgot. Why don't you just unscrew your metal thing now, so we don't have to do it later?"

"Master is very wise," he said. And, with a smile, Genos began to unscrew the metal plating that protected the wires in his would-be crotch area. Since he got an upgrade for a more human-like rear-end, the plating only covered the front, and screwed down about where an ordinary human's hip bones would be. The plating popped off, and Genos retracted the small screwdriver from his finger.

"Okay, Master. I am ready."

"Lift your legs."

"Yes Master."

Saitama slid the panties up along Genos' legs, silently drinking in the sight of the way the green lace danced with the gunmetal and the black. Genos' beauty was not unconventional to Saitama in the slightest. It was simply a fact of life. Genos was beautiful, and his. When he pulled the panties over Genos' ass, he couldn't help the light squeeze he gave it, causing Genos to shift his legs in the air, and Saitama to smirk in turn.

Moving on to the bralette, he lifted his cyborg up to slide the garment underneath him, and took his arms through the straps. He hooked the front of the bralette, and moved to grab the stockings. He rolled them on slowly, kissing the inside of Genos' leg when he reached the top. Finally, he slipped the heels on him.

Nothing made Genos feel sexier than when Saitama handled him like this. Not only did it make him feel sexy, but it made him feel more human than he had ever felt since becoming a cyborg. Before meeting Saitama, feeling human was something that he had no interest in experiencing, but now he was learning to coexist as both machine and human. He felt more at peace with himself because of it.

"Now what do you want me to do, Master?"

Saitama hummed in thought.

"Really, I just want to lie down with you right now. And then I'll make us dinner. Don't want you to lift a finger tonight. And then we'll make love. Any objections?"

"None at all Master."

* * *

After a dinner of dumplings, and the dishes were washed and put away, the two lovers were seated on their futon.

"I'm just so impressed in how much you've improved, Genos," he said, kissing his lover's neck, "I want to make this good for you because you deserve it."

"You're always incredible, Master," he said, leaning his head back, sighing.

"Mm. So are you~"

Still kissing his neck, Saitama gently pressed Genos to the futon. He straddled his cyborg and kissed up his neck, to the jawline, all the while holding his wrists down. He moved to kiss Genos on the lips, and the cyborg immediately opened his mouth, letting the kiss deepen.

The kiss lasted a while, for the two of them were in no hurry. They moved nice and slow, giving Genos time to work up an appetite- the ribbons of steam escaping his vents as evidence. The day's final rays of light caught the water droplets in rainbows, and the soft sounds of their kissing and shifting fabric filled the air. Saitama drew his lips away ever so slightly, causing Genos' eyes to flutter open, full of contentment and love, all for his Master. Such an expression was something Saitama never dreamed could ever be for him. Any ennui, self-loathing, or angst Saitama felt dissolved in the in those eyes. He could stare at his cyborg for ages without tiring, and feel any and all self-doubt replaced with purpose, drive, and happiness even. The manic little brat made the blood pump so hard in his veins, filling him that with purpose and drive, and he was in far too deep to even think of letting that feeling go at this point. He was hooked.

Genos, on the other hand, felt grounded in those brown eyes. His life was nothing but destruction and rampage and hatred, but his Master was the eye of that storm. All of the tranquility he never knew he desired rested in Saitama.

Indeed, the two of found balance in each other.

They silently acknowledged this sentiment as Genos' hips shifted upward- the friction stirring the blood in Saitama's veins.

A hum from Genos and a grunt from Saitama sounded through the mostly-quiet room. Saitama moved his hand from Genos' wrists, and scooped him up to a sitting position. From there his fingers dipped into the gaps of his back, massaging into wires. He watched his cyborg's seemingly-permanent scowl relax into pleasure. His brash voice softened into sweet moans and whimpers. The body he held so rigidly most of the time slumped into his touch.

"Look at you. You're beautiful," is what Saitama always said. The smile that Genos made whenever he said it, grew slightly bigger each time he said it. Saitama wanted nothing more than to see that smile radiate and reflect Genos' own budding self-worth. He was making progress after all. The more Saitama could help him with self-preservation, then hopefully the more value Genos would see in his own existence.

This effort wasn't lost on Genos. In fact, he could catch his own reflection in the mirror now and see a young man, or a young person-given how he felt that day- but a person nonetheless. He acted with caution now, not only because Master wanted it, but because _he_ wanted it for _himself._ He wanted a life after he got his revenge. Yes, the life he wanted was with Saitama, but it wasn't as simple as a codependent romance. The two had aspirations together. Their professional and personal lives merged, but it was still worth the distinction. They had a _world to conquer_ together.

However, in this moment they had each other to conquer. Sure Saitama indicated that he wanted to make this about Genos, but Genos simply couldn't help himself when he shifted onto his lover's lap, rolling his hips hard and slow.

" _Mmmph_."

"Feel good?"

 _"Shit_ , Genos."

" _Hmm_ ~"

The villains stayed like this for a while, hips moving together at different speeds. Soft grinding and teasing smiles. Hard rolling and desperate moans. As Saitama panted, his lover's vapor collected in his mouth, utterly engulfing him in their passion.

Saitama pressed Genos back down, and got on his knees. He lifted Genos' ass and legs, carefully pulling the panties off to leave the stockings and heels in place.

"Wanna be eaten out?"

As if that was a question! Genos did not think he had ever turned down such an offer. Just the same, he obediently nodded.

"Yes, Master. Please."

Saitama pulled Genos' legs over his shoulders, turning his head to kiss and nuzzle at his calf, and finally kissing down to between his legs. He sucked and bit and tugged, gently working his lover into a frenzy.

"Ah! Master!"

Genos' wires could not tell the difference between Saitama's mouth, fingers, or dick, but the intimacy of oral stimulation turned him on even more. It was physical and psychological. While he couldn't _feel_ that those were Saitama's teeth sweetly nibbling his cables and wires, he knew it and he moaned just as sweetly. There was a tender distinction. Oral felt like the most intimate conversation the two of them could have. And the silent communication extended as the lovers watched each other. Genos reveling at the hungry look in Saitama's blown-out eyes. Saitama watching Genos' expression soften and lose focus as he brought pleasure to him.

His cyborg was sexy almost to a fault, and he felt himself getting harder and harder. Both of his arms wrapped around Genos' waist, pulling him closer to his mouth, moving his head as he licked and tugged.

" _Ah_ , Master. _Ahn_."

"Mmm."

"Yes~!"

"Mmhmm~"

Genos rocked into Saitama's mouth, feeling the sparks jolt faster through his body. So close.

"Master," he slurred, "I'm going to- _AAAAAAHH~_!"

Saitama buried his face deeper in those wires, sucking a large bundle of them, drool pooling at the corners of his mouth, working and working at him, desperate to get him off.

And get him off Saitama did. Genos felt his core burn bright, static jumping through his circuits, steam billowing around them. It was far too much pleasure for him to even make a sound. Laboured pants softened into deep breathing as he came down, looking back at Saitama with half-lidded eyes.

"Fuck, Genos you're so hot."

He turned his head away, a little embarrassed. Sure Genos knew he was sexy, and he owned that, but hearing it from Saitama humbled him. Usually he doubted whether Saitama could have ever understood the effect he had on him. How he worshipped him.

"Aww Roomba, come on, look at me," he whined, hunkering down to lay on top of Genos, catching him in a kiss, "I love you~"

"And I love you."

"Think you can handle another round?"

"Always for you, Master."

"It should be for you, too."

"I always desire you, Master."

God the things that flowed so easily from his mouth! Of course, Saitama felt the same, but he preferred to express himself physically. Through several kisses he did so, making little indulgent noises of pleasure, and running his fingers through his hair. Utterly content like this, and still riding on the high of his orgasm, a small sigh escaped Genos' nose. His hand ran down Saitama's side, reaching down to grope his ass. Saitama twitched a little at the touch, deepening the kiss. Their legs tangled together as they just made out for a while- giving Genos some time to recover.

Finally, he reluctantly pried himself away from Genos, pulled off his own underwear, and grabbed the condom he had set nearby. Genos sat up and took the hand that was holding the condom.

"May I put it on you, Master?" Genos asked.

"What, the condom?" asked Saitama, a little confused.

"Yes, Master," he said.

"Why, though?"

"It always looks… satisfying… when you do it." Indeed, from beyond a sexual standpoint, Genos found himself quite fascinated by Saitama's anatomy.

"Sure," said Saitama, turning his hand to drop the condom in Genos'. He didn't really get it, but whatever made him happy.

Genos carefully tore open the envelope containing the condom, and pulled it out, examining the rolled up latex for a moment, the lubricant on it made it somewhat slippery. He rolled it on Saitama slowly, watching him shiver a little at his touch. Leaning forward as he finished putting the condom on, he kissed Saitama down back on the futon.

"Mmm, what are you doing, Roomba? I'm supposed to be doing all of the work," said Saitama, putting an arm behind his head.

"Doesn't this do more for me than it does for you, Master?" Genos asked, straddling Saitama.

Genos had somewhat of a point. It took longer for Saitama to get off like this, but that didn't change how undeniably sexy Genos looked when he rode him. It was a fair trade.

"Go ahead, then~"

That was all Genos needed to hear. He hovered over Saitama's cock for a moment, and dropped down.

Without getting the chance to recover, Genos starting bouncing up and down his lover's dick with no mercy, moving his hands to pull his wires taut for Saitama.

"Sh-iit, Roomba."

"Mm~ Ah~ M-master. Feels. So. Good."

Groaning, Saitama looked up at his lover- vision clouded by lust and steam. His cyborg's dark hair flew back with every drop, eyes reduced to silver slits, mouth hanging open, drooling, dripping with the most delicious moans. Squeezing his hips, he guided Genos' movements, letting his silicone ass smack against his skin.

"Ohhh, Genos~ god, fuck you're hot," he grunted.

And at this point, Genos was not shy to own up to his Master's sentiments because he _felt_ hot. Felt so hot to be working himself into a frenzy on Saitama's cock. Felt so hot to draw those sweet moans from Saitama. Felt so hot, _so hot,_ when that cock slammed against that perfect hookup- disturbing his electrical currents- making him so close to slamming into a wall of ecstasy.

"Yes~! God, yes~! Aaah!" Lewd whines spewed from Genos as he got so close that it was difficult for him to keep going on.

Saitama was all too familiar with that sign. Lifting Genos up slightly, he picked up where his lover left off, thrusting as hard has he could without breaking him. Hitting that hookup over and over.

A silicone-padded hand slapped onto Saitama's chest, as Genos' mouth gaped wider, producing no sound as he was fucked into so good.

"Yes Roomba, come for me, come for me~" he goaded.

Genos all but screamed in rapture, digging his fingers into Saitama's chest, orgasm hitting him so hard that he felt static crack throughout his whole body.

And Saitama felt it, too- the latex did nothing to insulate the high voltage sparks travelling down his dick.

" _Auuuuuuhhh shiiiiiiit_ ~"

The electricity brought Saitama to his own orgasm, made him come so hard that his vision went spotty, and his ears rang. The two reveled in the bolts before Genos collapsed on top of Saitama, dead weight, head reeling.

"Huuhhh, Master," he panted, utterly blissed out.

"God Genos, I think you electrocuted me," Saitama breathed, trying to catch his breath, skin still tingling.

Genos' head snapped up.

"Are you okay, Master?! I am so sorry, let me-"

He was cut off by a passionate kiss that took up the last of Saitama's energy.

"Don't even worry about it. It felt really good actually," he said brushing a thumb over Genos' cheek after breaking the kiss.

"Do you mean it, Master?" asked Genos, leaning into soft texture of Saitama's thumb.

"Oh yeah," he said, moving Genos from on top of him, and pulling out slowly, "We gotta try that again sometime. How'd it feel for you?"

"Mmm. Good~" he said, stretching out on the futon, putting an arm behind his head.

Saitama knew he'd done a good job if he could fuck the extensive vocabulary out of Genos. Smirking, he tied off the used condom, gave Genos a quick kiss, and got up to throw it away.

After a quick bathroom break, and putting on clean underwear, Saitama returned to the living area to discover that his cyborg was sound asleep- his heels kicked carelessly to the other side of the room. Job well-done, indeed. A fond smile radiated from him, as he moved to nestle next to his lover, pulling the heart-pattern comforter over the two of them.

"Love you~" he whispered as he wrapped his arms around Genos' waist. He rested his face on his chest, letting the sounds of fans and a humming core lull him to sleep.


End file.
